Valentine D L, Reeburgh W S
Department of Earth System Science, University of California, Irvine 92679-3100, USA.
Environ Microbiol. 2000 Oct;2(5):477-84. doi: 10.1046/j.1462-2920.2000.00135.x.
Anaerobic methane oxidation is a globally important but poorly understood process. Four lines of evidence have recently improved our understanding of this process. First, studies of recent marine sediments indicate that a consortium of methanogens and sulphate-reducing bacteria are responsible for anaerobic methane oxidation; a mechanism of 'reverse methanogenesis' was proposed, based on the principle of interspecies hydrogen transfer. Second, studies of known methanogens under low hydrogen and high methane conditions were unable to induce methane oxidation, indicating that 'reverse methanogenesis' is not a widespread process in methanogens. Third, lipid biomarker studies detected isotopically depleted archaeal and bacterial biomarkers from marine methane vents, and indicate that Archaea are the primary consumers of methane. Finally, phylogenetic studies indicate that only specific groups of Archaea and SRB are involved in methane oxidation. This review integrates results from these recent studies to constrain the responsible mechanisms.
厌氧甲烷氧化是一个在全球范围内具有重要意义但却鲜为人知的过程。最近有四条证据线索增进了我们对这一过程的理解。首先，对近期海洋沉积物的研究表明，产甲烷菌和硫酸盐还原菌的共生体是厌氧甲烷氧化的原因；基于种间氢转移原理，提出了“逆向产甲烷作用”机制。其次，在低氢和高甲烷条件下对已知产甲烷菌的研究无法诱导甲烷氧化，这表明“逆向产甲烷作用”在产甲烷菌中并非普遍过程。第三，脂质生物标志物研究从海洋甲烷排放口检测到同位素贫化的古菌和细菌生物标志物，并表明古菌是甲烷的主要消耗者。最后，系统发育研究表明，只有特定的古菌和硫酸盐还原菌群体参与甲烷氧化。本综述整合了这些近期研究的结果，以确定相关机制。
